Phonons in Perfect Crystals

摘要: In writing this article we have kept in mind the fact that two articles dealing with aspects of lattice dynamics already appeared Vol. VII series [9], [10]. The subject has however undergone very considerable development intervening decade. particular, experimental technique neutron inelastic scattering made possible determination form phonon dispersion curves for practically first time, and unexpected features interatomic forces become apparent. Secondly, new mathematical techniques it to evaluate influence anharmonic effects on physical properties crystals almost as much detail these had been worked out formerly basis harmonic approximation. We therefore devoted a part developments. order make account more nearly complete, included sections (notably A C) which cover same ground was covered by Blackman [9] Leibfried [10]; where discussed topics concerned from different approach. an Appendix summarised principal theory thermodynamic Green’s functions, applied evaluation those involve phonons.